(a)a soccer player kicks a rock horizontally off a 35 m high cliff into a pool of water. if the player hears the sound of the splash 2.83 s later, what was the initial speed given to the rock (in m/s)? assume the speed of sound in air is 343 m/s.(b)what if? if the temperature near the cliff suddenly falls to 0°c, reducing the speed of sound to 331 m/s, what would the initial speed of the rock have to be (in m/s) for the soccer player to hear the sound of the splash 2.83 s after kicking the rock?

a)v=15.83 m/s

b)v=14.89 m/s

Explanation:

a)

In y direction

Given that h=35 m and initial velocity is zero.

So

t=2.67 sec

It means that rock hit water after 2.61 sec.

Given that player hears after 2.83 sec.

Δt=2.83 - 2.67 s

Δt=0.16 sec

So distance travel by sound wave

d= C x Δt

C= 343 m/s

d= 343 x 0.16

d=54.88 m

From diagram

x=42.27 m

Now

x = v x  t

v=42.27/2.67

v=15.83 m/s

b)

Now sound speed have been changed

So new d

d=331 x 0.16

d=52.96 m

New x

x=39.75

So new velocity v

v=x/t

v=39.75/2.67

v=14.89 m/s

answer: strength i guess

explanation:

current flows in a wire